Interpreting a weird and scenic landscape to park visitors : tectonic and volcanic processes of Craters of the Moon National Monument and Preserve, Idaho PublicDeposited

Descriptions

This thesis develops a geology training manual for the Interpretation staff of
Craters of the Moon National Monument and Preserve (CRMO) in southern Idaho. The manual will help the staff convey geologic principles to park visitors who are
experiencing a landscape formed by volcanic processes. Basic geology and the most
current research on local and regional levels are incorporated in ways that are
understandable to the park’s staff and meaningful to park visitors. Interpretive staff are thus encouraged to include more geological concepts into their own interpretive programs than they might otherwise.
Chapters of the manual are divided into explanations aimed at a non-geologist
audience, with less-technical explanations of the most current research, followed by
explanations for a geologist audience that include more technical explanations and
summaries of the most current research. The first chapter presents concepts of geology that are universal to interpretation at National Park Service sites involving
volcanic features and processes. It includes basic explanations of plate tectonics and volcanism, emphasizing basaltic magmas and their eruptive products. The next chapter gives a broad geological perspective of the CRMO area by emphasizing ongoing hotspot and continental rifting processes. This includes an overview of the Yellowstone Plateau, the eastern Snake River Plain, and northern Basin and Range Province. The chapter provides a perspective on CRMO’s spatial and temporal positions along the Yellowstone hotspot track as well as within the Basin and Range continental rift zone. The overview explains the decompression melting responsible for volcanism at hotspots and continental rift zones. With this background information, the final chapter presents the geology of the Great Rift Zone and the Craters of the Moon (COM) lava field and their development through a sequence of lava flows during the past 15,000 years. This leads to discussions of the many volcanic features found within the COM lava field, such as craters and cinder cones and the types of lava flows.
The final chapter presents my own detailed research and geological mapping of the eruptive and non-eruptive fissures present in the CRMO Wilderness. The fieldwork is of the type that can be readily conveyed to the park staff and to the visiting public. I also synthesize research that has been published on the mechanisms for the injection of basaltic magma into dikes and formation of non-eruptive fissures in
the eastern Snake River Plain and Craters of the Moon National Monument and
Preserve. Presentation of this research will aid geological interpretation at CRMO by giving the interpretive staff a clearer picture of the similarity of Basin and Range
extension to the patterns of ongoing extension and volcanism at CRMO.
In each chapter, there are topics devoted to geological interpretation methods that can be used by the CRMO staff on particular topics. I have included methods that I developed in my two summers as an Interpretive Ranger at CRMO, along with other methods that have been used successfully by the park’s Interpretation staff in the past.